When the body and/or the chassis of a vehicle involved in an accident is to be repaired, e.g. with the aid of a reshaping apparatus of the type described in my prior U.S. Pat. No. 4,221,122, it is customary to use a jig with adjustable markers whose tips indicate the relative positions of characteristic points of the structure to be reshaped. Since vehicles of different makes or types generally vary in the locations of these characteristic points, separate lists must be consulted for the adjustment of the markers of such a jig preparatorily to its use with a given model. Such adjustment is laborious and often inexact since the markers, which usually are in the form of extensible rods, may have been deformed so that their tips do not occupy the proper locations even if their bases are precisely positioned according to scale graduations present on the jig. The maintenance of a fixedly preset jig for each type of vehicle, on the other hand, is a space-consuming and expensive undertaking, aside from the need for an occasional updating of the settings.